On the top right-hand corner of your dashboard page, you will see a gear symbol. Click that symbol to open the menu displayed below. From here, you will click the button labeled "Widgets."

You will be presented with a screen similar to the one below. This is the Manage Widget screen. The left half of the screen will display all widgets that your user has permissions to. On the right half, you will see a rough approximation of the widgets currently on your dashboard and their respective orientation.

Using the left half of the screen, scroll to the widget you want to add, then select the "Add To" button. A representation of the widget will appear on the bottom of the right half of the screen. You can then drag the widget to where you would like it to appear. The layout of the widgets on your dashboard can also be changed from the dashboard by simply grabbing the widget and dragging it to the desired location